Quake, tsunamis kill more than 700 in Chile
Television images showed houses washed away by swirling waters, cars tossed into shattered buildings and boats lifted into the streets in coastal towns including Pelluhue and Constitucion, where 350 deaths alone were reported.
"It's an enormous catastrophe ... there's a growing number of missing people," Bachelet said, adding that food and medical aid was being sent to help the roughly 2 million people affected by the quake.
The quake wrecked hundreds of thousands of homes, mangled highways and bridges and dealt a heavy blow to infrastructure in the world's No. 1 copper producer and one of Latin America's most stable economies.
Widespread disruption to the power supply threatened to hamper Chilean industry's recovery, although Chile's biggest copper mines slowly resumed operations on Sunday.
Copper prices surged in early trading on Monday due to supply worries caused by the earthquake in Chile, jumping 5.6 percent on the London Metal Exchange .
Giant waves set off by the quake crashed hundred of meters into coastal villages near the epicenter, demolishing houses and sending residents fleeing into the hills.
"I've got nothing left but what I'm wearing. We ran desperately up the hill and watched how the sea washed everything away," an unidentified woman from the fishing village of Duao told state television.
The government had told Chileans immediately after the quake that there was no danger of a tsunami, an error it said was based on incorrect data from navy experts.
In the hard-hit city of Concepcion, about 310 miles (500 km) south of Santiago, about 60 people were feared to have been crushed to death in a collapsed apartment block where rescuers worked through the night to find survivors.
A lack of water, food and fuel sharpened the hardship for the hundreds of thousands of people left homeless.
The government imposed a night-time curfew in Concepcion and the Maule region in a bid to stop looting and army troops began to arrive in the city late on Sunday. Television also showed images of police firing tear gas at looters in Santiago and of youths throwing rocks at officers.
Police earlier used tear gas and water cannons to disperse a crowd of looters carrying off food and electrical appliances from one supermarket in Concepcion.
Television images showed people stuffing groceries and other goods into shopping trolleys in Concepcion, and a local official in Santiago confirmed that at least two supermarkets there had been looted.
"People have gone days without eating," said Orlando Salazar, one of the looters at the supermarket. "The only option is to come here and get stuff for ourselves."
Concepcion's mayor, Jacqueline van Rysselberghe, said the situation was getting "out of control" due to shortages of basic supplies and called for troops to be sent to the city.
The quake poses a daunting reconstruction challenge for President-elect Sebastian Pinera, who takes office in two weeks.
Crushed cars, fallen power lines and rubble from wrecked buildings littered the streets of Concepcion, which has about 670,000 inhabitants and lies 70 miles (115 km) southwest of the quake's epicenter.
A string of strong aftershocks have rocked the country and thousands of Concepcion residents camped out in tents or makeshift shelters, fearing fresh tremors could topple weakened buildings.
Some economists predicted a deep impact on Chile's economy after the quake damaged its industrial and agricultural sectors in the worst-hit regions, possibly putting pressure on its currency.
The economic damage from the quake could be up to $30 billion, equivalent to about 15 percent of Chile's gross domestic product, said Eqecat, a firm that helps insurers model catastrophe risks.
Chile's fourth-largest copper mine El Teniente, which accounts for more than 7 percent of national output, resumed operations on Sunday. The nearby Andina mine was also due to resume operations but analysts feared power outages could still curtail supplies.
Production also resumed on Sunday at the Anglo-American Los Bronces copper mine, one of the company's two mines where power outages halted output, a union leader told Reuters.
Santiago's airport started to receive international flights for the first time since the quake struck. Officials said the runways were unscathed but the terminal building was damaged.
The quake triggered tsunamis as far afield as Japan and Russia, but there were no immediate reports of injuries or serious damage.